1. Field of the Invention
This invention relates to a dry-break coupler that can be connected in series with a valved adapter to define a flow passage for fluid. Upon separation, internal valves within both the coupler and the adapter block fluid flow therein towards the opposite member.
2. Description of the Prior Art
Known dry-break couplers have internal valves for regulating fluid flow. These couplers also have external couplings for attachment to adapters. Controls are required for operating both the valves and the couplings. It is necessary for an operator to hold the coupler in a coupling position with the adapter, then operate the controls for latching the coupler to the adapter and for opening the valve so as to allow fluid to flow from the coupler into the adapter. These operations can be difficult to perform by a single operator, since they normally require the use of both of the operator's hands to operate the control. Often the operator uses his body to hold the coupler in position with the adapter, while he operates the controls with his hands. Should the operator inadvertently open the valve before the coupler is latched to the adapter or should he unlatch the coupler before the valve is closed to block the flow of fluid, an accident would result, unless safety control features were provided to prevent such action.
Dry break couplers having internal valves for preventing the loss of fluid from an uncoupled coupler are shown in U.S. Pat. Nos. 3,473,569; 3,474,827; 3,884,448; and 3,897,091. Cams for operating valve closure elements are shown in U.S. Pat. Nos. 806,970 and 2,662,721. A coupling latch with a pivotable pawl that is controlled by a double pivotally connected handle is disclosed in U.S. Pat. No. 3,897,091. An interlocking mechanism that includes a disc with two arcuate cut-outs, on diametrically opposite sides of the disc periphery, for receiving cylindrical members is shown in U.S. Pat. No. 3,693,655.
In view of the prior art, there remains a need for a dry-break coupler that is light in weight, that can be readily handled, that can be operated by one hand of an operator with the same hand performing both the coupler latching operation and valve opening operation, that has safety features to prevent inadvertent operations by the operator resulting in accidental loss of fluid, that has a single guide system for the valve closure element to prevent such element from binding, and that has a simple clamping mechanism for latching the coupler to an adapter.